Road Signs Off By Few Kilometers

If you don`t have a calculator in your car, but you have a feeling those new traffic signs that post the speed limit in both miles and kilometers per hour are wrong, you`re right.

They`re wrong on purpose. Sort of.

The signs, which are gradually being installed on all state roads, were mandated by the state Senate in 1982. They are supposed to post the speed limit in miles per hour and the corresponding figure for kilometers per hour.

They do, but all the posted figures for kilometers per hour are off, some by as much as 8 kph.

For example, the 30-mph signs show the corresponding kilometer figure as 40 kph. It should actually be 48.28 kph.

Nobody miscalculated, according to Tom Hall of the Florida Department of Transportation. Instead, the kph figures were rounded off, downward, to the nearest 10-kilometer increment, at the insistance of federal highway officials, said Hall.

Except in the case of 55 mph, which is also posted at 88 kph, which is pretty close to the actual figure of 88.51 kph.

Confused?

You`re not the only one.

``I`m not sure if there was any rationale to it,`` said Hall.

A kilometer equals approximately 0.62 miles.

Thus, 20 mph is actually 32.40 kph. Instead, the signs post 30 kph.

The others are as follows:

-- 25 mph, posted as 40 kph, should be 40.23 kph.

-- 35 mph, posted as 50 kph, should be 56.33 kph.

-- 40 mph, posted as 60 kph, should be 64.37 kph.

-- 45 mph, posted as 70 kph, should be 72.42 kph.

-- 50 mph, posted as 80 kph, should be 80.47 kph.

-- 55 mph, posted as 88 kph, should be 88.51 kph.

``Three of them are roughly accurate,`` noted Hall.

``We`ve had an occasional citizen point out the inaccuracies to us, but we aren`t aware of any problems related to it,`` he said. ``Fortunately, all law enforcement agencies adhere to miles per hour as the standard.``